2 files changed, 12 insertions, 64 deletions

diff --git a/src/_functions.scss b/src/_functions.scss
index d091afa..236b548 100644
--- a/src/_functions.scss
+++ b/src/_functions.scss
@@ -9,6 +9,7 @@
 /// @access public
 ////
 
+@use 'sass:map';
 @use 'sass:math';
 @use './vars';
 
@@ -65,9 +66,11 @@
 @function list-slice($list, $start: 1, $end: length($list)) {
     $result: ();
 
-    @for $i from $start through $end {
-        @if $i != 0 {
-            $result: append($result, nth($list, $i), list-separator($list));
+    @if $end >= $start {
+        @for $i from $start through $end {
+            @if $i != 0 {
+                $result: append($result, nth($list, $i), list-separator($list));
+            }
         }
     }
 
@@ -162,67 +165,11 @@
 ///
 /// @return {any} Either the value assigned to $key or $default
 ///
-@function map-get-default($map, $key, $default) {
-    @return if(map-has-key($map, $key), map-get($map, $key), $default);
-}
-
-///
-/// Get the value for a map within a map (or deeper).
-///
-/// @param {map}           $map
-/// @param {string | list} $key
-/// @param {any}           $default [null]
-///
-/// @return {any} Either the value assigned to $key or $default
-///
-@function map-get-deep($map, $key, $default: null) {
-    $value: null;
-
-    @if type-of($key) == list {
-        $value: $map;
-
-        @each $k in $key {
-            $value: map-get($value, $k);
-
-            @if $value == null {
-                @return $default;
-            }
-        }
-    } @else {
-        $value: map-get($map, $key);
+@function map-get-default($map, $key, $keys...) {
+    $default: nth($keys, length($keys));
+    $keys:    list-slice($keys, 1, length($keys) - 1);
 
-        @if $value == null {
-            @return $default;
-        }
-    }
-
-    @return $value;
-}
-
-/// 
-/// Merge two maps recursively.
-///
-/// @param {map} $map1
-/// @param {map} $map2
-///
-/// @return {map} The result of a recursive merge of $map1 and $map2
-///
-@function map-merge-recursive($map1, $map2) {
-    @if type-of($map1) != map or type-of($map2) != map {
-        @error 'Two maps expected.';
-    }
-
-    $result: $map1;
-
-    @each $key, $value in $map2 {
-        @if type-of(map-get($result, $key)) == map and type-of($value) == map {
-            $result: map-merge($result, ($key: map-merge-recursive(map-get($result, $key), $value)));
-        } @else {
-            $result: map-merge($result, ($key: $value));
-        }
-    }
-
-    @return $result;
+    @return if(map-has-key($map, $key, $keys...), map-get($map, $key, $keys...), $default);
 }
 
 /// 
diff --git a/src/_props.scss b/src/_props.scss
index db24dff..196e2f9 100644
--- a/src/_props.scss
+++ b/src/_props.scss
@@ -10,6 +10,7 @@
 /// @access public
 ////
 
+@use 'sass:map';
 @use './functions';
 @use './contexts';
 
@@ -127,7 +128,7 @@ $namespace-context-id: 'namespace' !default;
 
     @if map-has-key($trees, $tree) {
         @if $merge {
-            $map: functions.map-merge-recursive(map-get($trees, $tree), $map);
+            $map: map.deep-merge(map-get($trees, $tree), $map);
         } @else {
             @error 'Property tree #{inspect($tree)} does already exist.';
         }